The present invention relates to a process for the solvent extraction of active compounds from chicory root and especially roasted chicory root. The present invention further relates to the extract obtained by this process, which has particularly valuable properties, especially in the field of oral hygiene. The present invention further relates to a toothpaste and a mouthwash containing the extract of the invention.
The root of wild chicory, also known as Cichorium Intybus Linn (abbreviated to CIL in the remainder of the present text), has been used since ancient times in the field of foodstuffs and for its medicinal properties.
In the field of foodstuffs, chicory root is often used after roasting. In the pharmaceutical field, on the other hand, it is roots dried in hot air which are almost exclusively used.
In 1983, Patel and Venkatakrishna showed the properties of roasted chicory root extract in the prevention of dental plaque and the treatment of gingivitis. The extract used by these authors is obtained by hot extraction from crude powder of dried and roasted chicory root in the presence of water or ethanol in a Soxhlet extractor.
The resulting extract is in the form of a black viscous liquid. This chicory extract, used in massage, affords a substantial reduction in inflammation of the gums, has antimicrobial properties and proves an effective inhibitor of dental plaque.
The present invention proposes a process for the solvent extraction of active compounds from chicory which differs from the process described above.
Characteristically, in the solvent extraction process of the invention, chicory is macerated in a solvent at a temperature of between 0xc2x0 C. and 6xc2x0 C. for a period greater than or equal to 12 hours, and the maceration liquor is filtered with a cut-off threshold of at least 0.22 xcexcm.
Filtration with such a cut-off threshold makes it possible to obtain a clear and active extract from any chicory maceration liquor, which is not obvious given that the active compounds of chicory have not yet been identified. However, it is not excluded, especially if the clarity is not prohibitive, to carry out the filtration with a higher cut-off threshold or to use other techniques to separate the extract and the solid residues.
It is also possible according to the invention, depending on the amount of solids extracted, to carry out one or more solid-liquid separation steps, optionally by filtration, before carrying out the filtration step on the maceration liquor with a cut-off threshold of at least 0.22 xcexcm.
Knowing that the solubility (and coefficients of diffusion) of the compounds contained in chicory, for example insulin, increases with temperature, it is therefore totally surprising that it is possible to extract active compounds from chicory root at the temperatures provided by the process of the invention. The low temperatures of the extraction process of the invention also allow good preservation of the resulting extract without the addition of preservative, since there is little development of the bacteria at the extraction temperatures of the process of the invention. Furthermore, the process of the invention avoids all thermal degradation of the chicory which might possibly denature the active compounds.
Likewise, the Applicant has also demonstrated that filtration down to a cut-off threshold of 0.22 xcexcm affords an extract which comprises all the active compounds and whose color and clarity are optimal for its subsequent use.
According to the invention, the amount of roasted chicory used is such that before maceration the dry matter content of the mixture of solvent plus chicory is at least 5% and preferably 7.4%. In fact, such amounts afford extracts which have or are capable of having the optimal pharmacological properties (antimicrobial and anti-inflammatory efficacy) and physical properties (turbidity, percentage of dry matter, color) for their subsequent use.
The chicory used within the framework of the present invention is not restricted to a specific category of chicory. For example, it can be dried chicory, roasted chicory or even the soluble chicory available commercially. In the case of roasted chicory, this is preferably obtained by a roasting operation whose final temperature does not exceed 170xc2x0 C., higher roasting temperatures causing undesirable changes such as a lowering of the extractable fraction and the pH, as well as a weak and pungent taste.
According to the invention, the roasted chicory can be in the form of grains, ground grains, powder, liquid or paste. Nevertheless, to optimize the amount of active compounds which can be extracted by the process of the invention, it is preferable to use powdered chicory so as to maximize the contact area between the chicory and the solvent.
The extract can be obtained with a sufficient clarity by filtering the maceration liquor with a cut-off threshold below or equal to 10 xcexcm.
There are no restrictions on the solvent used in the process of the invention, It can be a protic solvent, for example water or an alcohol. It is preferable to use water for reasons of both cost and safety, which proves advantageous for the subsequent uses of the extract obtained by the process of the invention.
The extract obtained by the process of the present invention can be used especially for the preparation of an oral hygiene composition. It can also be used for the preparation of a cosmetic composition. In fact, the extract obtained by the process of the invention has all the known properties of the chicory extract obtained by hot extraction, namely antimicrobial and anti-inflammatory properties, without having its use-limiting black color.
Preferably, the mouthwash of the invention contains an amount of between 8% and 12% by weight, preferably of 10% or approximately 10% by weight, of the chicory extract obtained by the process of the invention.
Likewise, the toothpaste of the invention contains an amount of between 8% and 12% by weight, preferably of 10% or approximately 10% by weight, of the chicory extract obtained by the process of the invention.
The present invention will be better understood and its characteristics and advantages will be more clearly apparent from the following description and Examples.